Solenoid



Aug. 4, 1942. w. A. RAY 2,291,599

SOLENOID Filed Deo. le, 195s f fa.

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B /Ax MM Gftorneg Patented "Augt 4, 1942 UNITED STATES PATENT OFFICESOLENOID William A. Ray, Glendale, Calif.

Application December 16, 1939, Serial No. 309,596

(ici. :U-341) 5 Claims.

My present invention relates to electromagnetic operators and inparticular to an alternating current solenoid operator employing areciprocable plunger.

It has been found that, in such an operator, it is essential to veryaccurately center or guide both ends of the plunger in order that theoperator shall be hum-free when energized. A typical example of meansfor that purpose is disclosed in Patent No. 2,098,195, issued to meNovember 2, 1937.

It is an object of my present invention to provide improved guidingmeans for a solenoid plunger, which means will assure accurate centeringof the plunger within the tube in which it is reciprocable.

In a solenoid operator of the type described, it is generally necessaryor desirable that guiding means for the outer end of the plunger beprovided as a separate member which, in assembly, must be accuratelysecured in position.

It is therefore aparticular object of my invention to provide a guidebushing for the plunger, and means for accurately centering the bushingwith respect to the plunger tube.

Other objects and advantages of my invention will be found in thedescription, the drawing, and the appended claims.

For complete understanding of the invention, reference may be had to thefollowing detailed description and accompanying drawing, wherein:

Figure 1 is a sectional view of a solenoid valve embodying my presentinvention; and

F ig. 2 is a fragmentary section taken along the line 2 2 of Fig. 1.

In the drawing, the solenoid operator of my invention is shown, by Wayof example, applied to a fluid control valve comprising a casing Ithaving an inlet and an outlet separated by a ported partition I2provided with a valve seat I3. Threadedly supported in an upperextension of said casing is a base member I4 for the operator, having acentral cylindrical opening therethrough wherein is sealingly securedthe lower end portion of a plunger tube I5 of non-magnetic material.

Reciprocable within said plunger tube is a plunger member I6, ofmagnetic material, the upper outer portion of which is generally squarein cross-section and has rounded corners conforming to the curvature ofthe plunger tube, as shown in Fig. 2. The diameter of the plunger acrossits corners is appreciably less than the inner diameter of the tube.

The upper end o1' the plunger tube is closed by a member Il ofnon-magnetic material carrying an outer ring i8 and a plunger stopmember i9, both of magnetic material. The lower end of the stop memberis of generally conical form and is cooperable, when the plunger is inits attracted position as shown, with a concentric recess formed in amagnetic number 29 which is carried by the plunger tube, a non-magneticmember 2i being interposed therebetween.

The magnetic function of the members referred to in the precedingparagraph has been described in detail in my Patent No. 2,098,195. Itsuces herein to state that the cooperating members I9 and 2li serve toaccurately center the upper end of the plunger in the tube when thesolenoid is energized by current flow in coil member 22.

Slidable in the bore of the cylindrical lower end portion 23 of plungeri6 is a rod 24 carrying on its lower end a valve member 25 cooperablewith the seat I3. This rod serves to provide impact action in theopening of the valve.

The lower end of the opening in the base member iii is outwardly taperedto receive a frustoconical guide bushing 26 having a concentric borewhich is a close sliding nt for the cylindrical lower end 23 of theplunger. A recessed wire snap-ring 2l retains the guide bushing 26tightly in position in the tapered seat or recess of member lll.Openings 28 permit fluid communication with the space surrounding theupper end of the plunger. A spring 29, compressed between the valvemember and a recessed bottom surface of the guide bushing 26, urges theplunger down- Ward.

It will be seen that, by my present invention, I have provided simple,effective means for ensuring the accuracy of centering of the plunger inproduction manufacture of solenoids.

I wish it to be understood that modications may be made in the specicembodiment of my invention, herein shown and described, Withoutdeparting from the spirit of my invention and that I intend therefore tobe limited only by the scope of the appended claims.

I claim as my invention:

1. In a solenoid operator, a plunger tube, a plunger reciprocable insaid tube, a base member for rigidly supporting an end portion of saidtube, a bushing for continuously and closely guiding said plunger, saidbase member being provided with a tapered recess in axial alignment withsaid tube and said bushing having a corresponding taper on its outerwall cooperable with said recess, and means for locking said bushingagainst movement in said recess.

2. In a solenoid operator. an spertured base member. a cylindricalplunger tube rigidly supported at one end in the aperture ofisaid basemember, a plunger freely reciprocable in said tube. s frusto-conicalmember having s concentric .cylindrical opening for closely guiding saidplunger throughout its complete stroke. sp0rtionoftheinnersidewallatthefreeendofthe aperture of said base memberhaving a corresponding taper .so as to receive said guide member inaxial alignment with said tube, the taper having substantial area ofcontact with the frusto-conical member. and means for retaining saidguide member against movement in said tapered aperture.

3. In a solenoid operator, a -base member having a cylindrical openingtherethrough, s cylindrical plunger tube rigidly supported in one end fsaid opening, the other end of said opening being outwardly tapered, aplunger freely reciprocable in said tube, a frusta-conical memberfitting the tapered end of said opening and having a concentric holetherethrough for continuously and closely guiding a portion of saidplunger whereby the plunger is maintained out of engagement with theinner wall of said tube. and

means for continuously retaining said guide member against movement insaid tapered opening.

4. In a solenoid operator. a base member having a cylindrical openingtherethrough, a cylindrical plunger tube rigidly supported in one end ofsaid opening. the other end of said opening being outwardly tapered. aplunger freely reciprocable in said tube, means mounted in the free endof said tube and engageable with one end of said plunger for centeringthe same 'in said tube. a frusta-conical member having a taper fittingthe tapered end of said opening and having a concentric holetherethrough for closely guiding the other end portion of said plungerthroughout its complete stroke. and means for continuously retainingsaid guide member against movement inthetaperedendofsaidopening.

5. In a solenoid operator. a base member having a cylindrical openingtherethrough@ cylindrical plunger tube closed at one end and rigidlysupported at its other end in one end of said opening, the other end ofsaid opening being outwardly tapered. a plunger freely reciprocable insaid tube, means mounted in the closed end of said tube and engageablewith one end of said plunger for centering the same in said tube. atruste-conical member having a taper fitting the tapered end of saidopening and having a concentric hole therethrough for continuously andclosely guiding the other end portion 'of said plunger. said guidemember having a passage therethrough communicating with the interior of`said tube, and means for continuously retaining said guide memberagainst movement in the ta- WILLIAM A. RAY.

